<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>数据驱动</title>
</head>

<body>
    <div>
        <div>商品数量<input id="goodsnum" /></div>
        <div>商品价格<input id="goodsprice" /></div>
        <div>小计<span id="total"></span></div>
    </div>
</body>
<script>
    let goodsnum = document.getElementById("goodsnum");
    let goodsprice = document.getElementById("goodsprice");
    let total = document.getElementById("total");

    let goodsinfo = new Proxy({}, { //监听对象的改变，只要对象发生改变就会被监听到
        set(target, attr, val) {
            target[attr] = val;
            console.log(target);
            console.log(attr);
            console.log(val);
            complier();
        },
        get(target, attr) {
            return target[attr];
        }
    })

    function complier() {
        total.innerHTML = goodsinfo.goodsnum * goodsinfo.goodsprice;
    }

    goodsnum.oninput = function () {
        goodsinfo.goodsnum = this.value;
    }
    goodsprice.oninput = function () {
        goodsinfo.goodsprice = this.value;
    }





</script>

</html>